This invention relates to improvements in tools which comprise a shaft connected with and projected from one face of a pad or disc the opposite face of which mounts an abrasively surfaced sanding, buffing or polishing device by means of interposed sheet material defining a releasable fastener one element of which is secured to the pad and the other element of which is secured to the back of the sanding, buffing or polishing device, the fastener being of a hook and loop type, such as Velcro or its equivalent. The invention provides improvements in (a) the means and the manner in which the shaft is interconnected with the pad, by virtue of which to insure a continuing, positive and uniform drive thereof in rotation, (b) the construction of the pad, which affords a more positive, more satisfactory and more durable mount thereto of that abrasively surfaced device which is selected to provide the working face of the tool so comprised and (c) the character and manner of interrelation with the pad of that portion of the fastener which is secured thereto, the net result of which is the achievement of a sanding, buffing and polishing tool which is simply constructed and most efficient and easy to use.
Prior art tools such as those with which the present invention is concerned have evidenced a number of problems in their use, which problems become particularly obvious where the application of the tool requires a high speed of its rotation. Such problems, which derive to a considerable extent from the degree of the pressure and torsional stress developed in use of the tools, include the following:
(a) hook portions of the sheet material providing one element of the fastener which forms a releasable connection of the abrasively surfaced working device to the pad become so embedded in the material in the second element of the fastener, to which they connect, as to make the abrasively surfaced device difficult to remove from the pad when its replacement is required or desired, PA0 (b) the inherently developed pressure and torsional forces result in such a bending and stressing of the aforesaid hook portions, in tension, as to fatigue the hook portions and at the same time diminish their value as connector elements, PA0 (c) under such conditions as set forth in subparagraph (b) immediately above, the portions of the material in which the hook elements engage are so strained, distorted and/or broken as to the diminish the value thereof in achieving the connection required between the abrasively surfaced working medium and the pad, as a consequence of which there is a radial shifting of the working medium relative the pad and/or a "walking" of the tool, making it difficult to satisfactorily perform therewith a sanding, buffing or polishing function, PA0 (d) the wear and tear on the abrasive surface of the working medium is often such as to consequentially induce such weakness in and/or distortion of the fastener sheet materials as to necessitate a frequency of replacement of parts much greater than normal, increasing beyond a reasonable level the time and/or cost of performing the required sanding, buffing or polishing of a work surface or surfaces, PA0 (e) the connection between the pad and the shaft through which it is driven loosens, as a consequence of which a satisfactory sanding, buffing or polishing of a work surface becomes quite difficult to achieve in any reasonable degree of time.
As those versed in the art will fully understand, the primary area of use of the abrasive surface of the device providing the working medium mounted to the pad will be in a location adjacent the outer peripheral edge of its working face. Considering further that the hook and loop connector portions of the tools of the prior art with which we are here concerned include portions thereof sandwiched between the abrasively surfaced device and the front face of the pad which they overlie, one can comprehend the seriousness of the problems of the prior art to which the present invention is directed.
The present invention deals with and overcomes the above mentioned problems in a very positive manner. The improvements which are comprised therein which lend themselves to the solutions of the problems will be illustratively described herein with particular reference to the embodiment thereof in which the pad and the abrasively surfaced sanding, polishing and buffing mediums applied thereto each has a disc form and the means defining the interconnection of the abrasively surfaced device to the pad define a hook and loop type releasable fastening of one thereof to the other. While so illustrated, neither the specific form nor the application thereof herein demonstrated should be construed as limiting since such is obviously not intended.
As far as those substantively involved in this disclosure, the following U.S. Patents and foreign publications represent the general state of the prior art of which they are aware, the same having been determined in the course of an extensive search of the records of the U.S. Patent and Trademark Office:
______________________________________ Country No. Date Inventor ______________________________________ U.S. 3,302,232 Feb. 7, 1967 T. J. Wasiloff et al U.S. 3,346,904 Oct. 17, 1967 William F. Armstrong U.S. 3,522,681 Aug. 4, 1970 G. Lampert U.S. 3,527,001 Sept. 8, 1970 R. H. Kleemeier et al U.S. 3,703,739 Nov. 8, 1972 Young et al U.S. 4,437,269 Mar. 20, 1984 George Shaw England 1,126,136 Sept. 5, 1968 Swiss 446,105 Oct. 31, 1967 ______________________________________
It does not appear that any one of these foregoing publications has specific pertinence to the novel features of the invention or sets forth any pertinence beyond that which is first defined in this disclosure as comprising a tool to which the improvements of the present inventon are directed.